// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

(function(mod) {
  if (typeof exports == 'object' && typeof module == 'object')
    // CommonJS
    mod(require('../../lib/codemirror'));
  else if (typeof define == 'function' && define.amd)
    // AMD
    define(['../../lib/codemirror'], mod);
  // Plain browser env
  else mod(CodeMirror);
})(function(CodeMirror) {
  'use strict';
  // declare global: JSHINT

  var bogus = ['Dangerous comment'];

  var warnings = [
    ["Expected '{'", "Statement body should be inside '{ }' braces."],
  ];

  var errors = [
    'Missing semicolon',
    'Extra comma',
    'Missing property name',
    'Unmatched ',
    ' and instead saw',
    ' is not defined',
    'Unclosed string',
    'Stopping, unable to continue',
  ];

  function validator(text, options) {
    if (!window.JSHINT) {
      if (window.console) {
        window.console.error(
          'Error: window.JSHINT not defined, CodeMirror JavaScript linting cannot run.',
        );
      }
      return [];
    }
    JSHINT(text, options, options.globals);
    var errors = JSHINT.data().errors,
      result = [];
    if (errors) parseErrors(errors, result);
    return result;
  }

  CodeMirror.registerHelper('lint', 'javascript', validator);

  function cleanup(error) {
    // All problems are warnings by default
    fixWith(error, warnings, 'warning', true);
    fixWith(error, errors, 'error');

    return isBogus(error) ? null : error;
  }

  function fixWith(error, fixes, severity, force) {
    var description, fix, find, replace, found;

    description = error.description;

    for (var i = 0; i < fixes.length; i++) {
      fix = fixes[i];
      find = typeof fix === 'string' ? fix : fix[0];
      replace = typeof fix === 'string' ? null : fix[1];
      found = description.indexOf(find) !== -1;

      if (force || found) {
        error.severity = severity;
      }
      if (found && replace) {
        error.description = replace;
      }
    }
  }

  function isBogus(error) {
    var description = error.description;
    for (var i = 0; i < bogus.length; i++) {
      if (description.indexOf(bogus[i]) !== -1) {
        return true;
      }
    }
    return false;
  }

  function parseErrors(errors, output) {
    for (var i = 0; i < errors.length; i++) {
      var error = errors[i];
      if (error) {
        var linetabpositions, index;

        linetabpositions = [];

        // This next block is to fix a problem in jshint. Jshint
        // replaces
        // all tabs with spaces then performs some checks. The error
        // positions (character/space) are then reported incorrectly,
        // not taking the replacement step into account. Here we look
        // at the evidence line and try to adjust the character position
        // to the correct value.
        if (error.evidence) {
          // Tab positions are computed once per line and cached
          var tabpositions = linetabpositions[error.line];
          if (!tabpositions) {
            var evidence = error.evidence;
            tabpositions = [];
            // ugggh phantomjs does not like this
            // forEachChar(evidence, function(item, index) {
            Array.prototype.forEach.call(evidence, function(item, index) {
              if (item === '\t') {
                // First col is 1 (not 0) to match error
                // positions
                tabpositions.push(index + 1);
              }
            });
            linetabpositions[error.line] = tabpositions;
          }
          if (tabpositions.length > 0) {
            var pos = error.character;
            tabpositions.forEach(function(tabposition) {
              if (pos > tabposition) pos -= 1;
            });
            error.character = pos;
          }
        }

        var start = error.character - 1,
          end = start + 1;
        if (error.evidence) {
          index = error.evidence.substring(start).search(/.\b/);
          if (index > -1) {
            end += index;
          }
        }

        // Convert to format expected by validation service
        error.description = error.reason; // + "(jshint)";
        error.start = error.character;
        error.end = end;
        error = cleanup(error);

        if (error)
          output.push({
            message: error.description,
            severity: error.severity,
            from: CodeMirror.Pos(error.line - 1, start),
            to: CodeMirror.Pos(error.line - 1, end),
          });
      }
    }
  }
});
